Retractable road wheel assembly for vehicle trailers



Jan. 5, 1954 e. M. TOMPKINS 6 3 RETRACTABLE ROAD WHEEL ASSEMBLY FOR VEHICLE TRAILERS Filed June 12. 1952 Patented Jan. 5, 1954 OFFICE RETRACTABLE ROAD WHEEL ASSEMBLY FOR VEHICLE TRAILERS George Maxwell Tompkins, Parktown West, Johannesburg, Union of South Africa Application June 12, 1952, Serial No. 293,106

Claims. 1

This invention relates to road vehicles in the form of trailers, and in particular to trailers which are required to be transported, without unloading, by both road and rail. Road vehicles are frequently too lofty to be loaded onto a railway wagon for transport although it would often be desirable to rail a loaded road vehicle, such as a trailer, transport it to the railway for movement by rail and at the end of the railway journey to move it again by road, without unloading, to its final destination. The object of this invention is to provide a trailer which can be moved on road and rail without unloading and yet will be low enough to afiord ample head room without loss of capacity when conveyed by rail.

According to this invention there is provided a road vehicle comprising a trailer having retractable road wheels mounted to swing from a position where they project below the vehicle to a position where they project from the ends thereof. The retractable road wheels are conveniently mounted on semi-elliptical springs, the

inner ends of said springs being provided with,

horizontal slides while their outer ends are attached to swinging straps by which the wheels are carried either in their running position or in a retracted position. The trailer is, by this provision, capable of being reduced in height to normal loading, and when loaded on a railway wagon is reduced in height to provide head room. Again when the trailer is fitted with a double deck the invention provides for its upper deck to be lowered substantially to ramp level for ease of loading.

Furthermore, the retracted wheels may be mounted so as to form buffers and wedging members for the body of the vehicle when carried on a railway wagon.

This invention is applicable both to the type of trailer which normally is transported on four wheels and also to the trailer which has its front end adapted to be carried on the rear of a tractor, or on a wheeled dolly or bogie which can easily be removed in the well known manner.

The four wheel type is illustrated somewhat schematically in the accompanying drawings, in which in all figures the road wheels are shown by dotted lines Fig. 1 is a side view of the vehicle ready for travelling on the road.

Fig. 2 shows a view of the vehicle mounted in a railway wagon.

Figs. 3 and 4 are views of part of the vehicle on an enlarged scale showing one method of 2. moving the road wheels from their running to their lowered position.

Fig. 5 shows an alternative construction to that in Figs. 3 and 4.

Fig. 6 shows the wheels mounted on turning rings.

Fig. 7 is an end View of the embodiment of Fig. 5 but to half the scale.

In the drawings there is illustrated a body l of a vehicle, such as a pantechnicon, mounted on road wheels 2, shown in dotted lines. The axles 3 are shown as carried on semi-elliptical springs 4.

The vehicle shown in Fig. 1 is again shown in Fig. 2, but mounted on a railway wagon 5. In this latter view the wheels 2 have been swung to the rear and upwardly and in this way the total height of the body I on the wagon 5 is sufiiciently low to clear the head room allowed by the railway.

To allow the wheels 2 to be swung from the position shown in Fig. 1 to the position shown in Fig. 2 the inside ends 6 of the semi-elliptical springs 4 are each carried in a slipper 7 adapted to be moved in a slide 8 which is secured to the chassis below the floor of the trailer. The other ends 9 of the springs 4 are hung from the ends of straps I0 which are rotatably suspended from the pins ll mounted in a bracket 12 secured to the body I. It will be understood that while only one side of the vehicle is described and shown the parts are duplicated on the opposite side and pins II will be carried through from one side of the vehicle to the other. Also the slippers i at each end of the vehicle are con nected together by rods passing between them and tying the ends of the springs 4 on the one end of the vehicle together.

By swinging the straps l0 about the pins II the slippers 1 are moved along the slide 8 to take up the position shown in Figs. 2 and 4. In this position the body I is no longer supported on the road wheels 2, but the wheels pro ject from both ends of the body I.

In swinging the wheels 2 from the position shown in Fig. 1 to that shown in Fig. 2, the body I has been lowered so that it rests on the floor of the railway wagon 5. During such lowering, said wheels 2 swing about the ends of the body I and in such movement they are moved out beyond the end of the body I and then back to rest against it. From such a position they may be returned slightly towards their road running position which will operate to move them outwards to jam them against the ends R3 of the 3 wagon or other fixtures and so act as bufiers and to clamp the body I fast by the resilient cushioning of the tyres of the wheels 5. i

To effect the desired movement of springs 4 to carry the wheels 2 from their running and their resting positions any suitable mechanism may be employed. In Figs. 3 and 4, the slipper 1 is shown as a nut threaded onascrewed rod [4 adapted-to be rotated through a bevel wheel I5; When the rod I4 is rotated so that the slipper 1 is screwed to the inside end thereof the semi-elliptical spring 4 is held so as to carry axle 3'and'wheels 2 in their runnin position and when tlie r'od His rotated in the opposite direction, to screw the slipper 1 to the outside end of rod; f4, the'whel's 2 are fully retracted as shown inFig'I 4.

Fig. 5 indicates another methodof swinging the wheels 2 from one position to the other. In this method the pin l I is secured to the straps ill to be rotatable therewith- Gear wheel I6 is keyed to pin i l= and the pinion I! is" show-n as meshing therewith. On the rotation-of gear IT, the ends 9 of the straps- I'U' are swun outwardly drawing with them the ends of the-spi ihgsdand moving shoe's 1- alongthe" slides 8;

Figs. 1 and 6 show the slide 8 furnished with turning-ringsl 8 toenable' tl-ie' front-wheels of the truck to swivel. l9 indicatesa d r aw bar;

It will-be noted that if the wheels 2' are in the position-sliown inFigE- 2 with the body" I resting on the" ground instead ofthe railway wagon as illustrated} it can e'ssiiyre loaded Without the necessity of lifting the load to the normal-floor height or the vehicle: I

AS an ei'tar'fiple' of a" further-use for this trailer itmay be'used for the traiisp' t of livestock-and in particular sheep or" pigs which are accommodated on a double-deck trailer Fig. 1 shows in dotted lihs 20 the pos'ition of the second deck. For loading, for instance, sheep from a" ramp; the trailer, backed up to the ramp, can have its normal floor 2-1 easily loaded and if it isprdVid'd Wi-th anus-per floor or deoklfl-the trailer is new lowered so that it'snor'ina'l 21 is at about ground level and the upper fiiior 21F is on a'lev'el ornanny on a level with'the loading ram-p and-can be loaded easilytherefrom. Having been loaded on both fioors 2i] and i the trailer is rais'ed by having" its WhelSZ sw ii hto place when it an be transporte by read oi wheeled onto a railway wagon 5'. the Wagon it is again lowere'd tothe floor of thesaiii soth'ait it provides head room-clearance. 'I-lie ofi loading is accomplished by a reverse of the loading method.

When the wheels 2' are brought to their carry ing or running position they may be locked against retraction in any'conveni'e'nt manner. In the embodiment shown in Figs. 3 andi nospeial locking device is required; In the embodiment shown in Figs. 1 and 2 a removable-pin 22 may be provided which is inserted in the brackets 12 to prevent the outward swing of strap H).

When the body I is heavily loaded the lowering and raising of it may be assisted by the use of suitable jacks, not shown.

This invention provides a trailer which can be lowered by swinging its wheels away from their carrying and running position, while at the same time allowing their withdrawal and repositiohingito be accomplishdasily and without the necessity for" a special crane or other lifting device other than the usual vehicle jack.

What I claim as new and desire to secure by hetters-Patent-is:

1. A road. vehicle comprising a trailer, a floor and endwallsfor the trailer, wheels mounted on 1 semi emptied springs, slides below the floor of thetiailer'; a) slipper in each slide and attached to one'end or the spring, a strap pivoted on the end wall of the trailer and attached to the other end of the spring, and means. for swinging the strap through approximately 2. A road: vehi'ol' erg-claimed m dairir 1 having a threaded nut oh" the slipperand-a-screwedfiod extending along. the length" of the slide and eh' gaging said nut'. V

3:- A road vehicle' comprising a trailer, 3 floor and end wens for the tranche pair of road wheels mounted on acommon': airlega pair'o'f se'ml -ellip' .tical springs for each air-1e; a-slipp'e'r for or ie erid straps, a supporton theefid of the" traiie'r f or'the rod, and means for rotating saidrod: With the straps attached thereto through 180";

4. A road vehicle as claimed cla'ii'ii 3 having gearing for rotating the rod ati'faohedto the straps.

5. A road vehicle c em nsihg a trailer a"- door and end walls for the trailer, two pairs ofroad wheels each pair mounted on a common axles pair of semi=lliptieal spr'i'ngs for each alt-1e; a slipper for one end of each-spring. a slid'eon th'e underside of the floor o'fitli'e trailer for each-slip per, a strap with one end attached to the' otli'o'f endof each sprin a conirhon rod attached to the other ends-0feach pair of straps, a-supporton the end of the trailer for the rod, and m'eansforro tating said rodwith the straps-attached thereto through 180".

GEORGE TOMPKINSa- References Cited in the file of this patent- UNITED PATENTS Number Name Date 2.05047; Soulis' Aug. I1, 1936 2,313,877 yce Mar; it, 19'43 2,518,602 crook A113. is, 1950 

